1. Field of the Invention
The present invention relates to a portable terminal, a program installed in a portable terminal, a communication method, and a communication apparatus.
Priority is claimed on Japanese Patent Application No. 2005-157887, filed May 30, 2005, the content of which is incorporated herein by reference.
2. Description of the Related Art
In recent years, a service called “IP push service” has become widely spread, in which data possessed by an upper device on a network is transmitted to a lower device possessed by a user or the like, at a timing different from a timing required by the lower device. FIG. 5 is a diagram showing the general structure of an IP push service system for providing the IP push service to a portable terminal such as a notebook (or personal) computer to which a wireless communication card can be installed.
In FIG. 5, reference numeral 100 indicates an IP push service terminal, reference numeral 101 indicates an IP push server, reference numeral 102 indicates an SMS (short message service) server, reference numeral 103 indicates a communication network, reference numeral 104 indicates a wireless base station, reference numeral 105 indicates a wireless communication card (i.e., a communication apparatus), and reference numeral 106 indicates a portable terminal.
The IP push service terminal 100 is a terminal such as a personal computer, possessed by an ISP (Internet service provider) for providing an IP push service to a user. Specifically, the IP push service terminal 100 commands the IP push server 101 via the communication network 103 to provide an IP push service to a user (i.e., the portable terminal 106).
The IP push server 101 stores various data used for the IP push service. When the IP push server 101 is commanded by the IP push service terminal 100 to provide the IP push service to the user, the IP push server 101 sends the above data to the user.
The SMS server 102 sends an SMS message to the user. The communication network 103 is an analog telephone network spread around various areas of the whole country.
The wireless base station 104, provided in each of specific service areas, is a relay station for connecting a portable communication terminal (i.e., the portable terminal 106 to which the wireless communication card 105 is installed) to the communication network 103 via wireless communication.
The wireless communication card 105 is a PC card for performing wireless communication with the wireless base station 104 by using a CDMA2000 1×EV-DO (code division multiple access 2000 1× evolution data only) method, or the like. The wireless communication card 105 is operated by receiving a power supply from the portable terminal 106.
The portable terminal 106 may be a notebook or personal computer possessed by the user. When the wireless communication card 105 is installed to the portable terminal 106, the portable terminal 106 can access the communication network 103 via the wireless base station 104.
The operation of the IP push service system having the above-described structure will be explained. First, the IP push service terminal 100 commands the IP push server 101 to provide the IP push service to the user. When the IP push server 101 does not know the IP address of the portable terminal 106, the IP push server 101 requests the SMS server 102 to send an SMS message to the portable terminal 106, where the SMS message is a message for requesting access to the IP push server 101 by dial-up connection.
In accordance with the request from the IP push server 101, the SMS server 102 sends the SMS message to the portable terminal 106. The portable terminal 106 is in an SMS reception standby state, and receives the SMS message from the SMS server 102 via the wireless base station 104 and the wireless communication card 105. The portable terminal 106 then analyzes the received SMS message, and starts dial-up connection, so as to access the IP push server 101.
The IP push server 101 can obtain the IP address of the portable terminal 106 by being accessed by the portable terminal 106. Therefore, the IP push server 101 can provide the IP push service designated by the IP push service terminal 100 to the portable terminal 106.
Published Japanese Translation, No. 2003-509920, of PCT International Publication, No. WO01/019110 discloses a technique relating to the IP push service system.
In the above operation, before the analysis of the SMS message is completed and the dial-up connection is started, the portable terminal 106 disconnects a modem port (i.e., a communication port) to which the wireless communication card 105 is installed. Accordingly, the wireless communication card 105 determines that usage of itself (i.e., the card) is terminated, and cuts off power supply voltage supplied by the portable terminal 106, so as to turn off the power of itself. When the portable terminal 106 starts dial-up connection, the wireless communication card 105 determines that usage of itself is started, and turns on the power of itself. In accordance with the turning-on of the power of itself, the wireless communication card 105 starts searching for the wireless base station 104, and dial-up connection is started after completion of the searching operation. As described above, in accordance with the disconnection of the modem port, power of the wireless communication card 105 is once turned off; thus, the operation of searching for the wireless base station 104 is again performed, thereby increasing the time from the reception of the SMS message to the completion of the dial-up connection.